Experimental correction of irregular corneal astigmatism using topography-based flying-spot-mode excimer laser photoablation.
OBJECTIVE
To present a novel experimental approach for treating irregular corneal astigmatism.


METHODS
After decomposition of topographic analysis data into orthogonal Zernike polynomials, a regular target surface was defined, and the ablation profile was calculated. In a polymethylmethacrylate with an irregular surface, computer-controlled ablation was performed using a 193-nm excimer laser in "flying-spot mode."


RESULTS
The difference between flattest and steepest hemimeridians in the 3-mm zone, surface regularity index, and surface asymmetry index were reduced from 8.7 to 1.1 diopters, 1.19 to 0.39, and 1.84 to 0.14, respectively.


CONCLUSIONS
Tying corneal topography into laser software offers a straightforward concept for correction of irregular corneal astigmatism in an experimental model.
Seitz
B
B
Department of Ophthalmology, University of Erlangen-Nürnberg, Germany. berthold.seitz@augen.med.uni-erlangen.de
Langenbucher
A
A
Kus
M M
MM
Harrer
M
M
D001251:Astigmatism / Q000601:surgery*; D003315:Cornea / Q000601:surgery*; D019781:Corneal Topography; D006801:Humans; D054018:Lasers, Excimer; D008953:Models, Anatomic; D018903:Photorefractive Keratectomy / Q000379:methods*; D019904:Polymethyl Methacrylate
D019904:Polymethyl Methacrylate